Mining machine



C. A. PRATT MINING MACHINE Sept. 24, 1935.

Original Filed June 15, 1932 2 Sheets-Sheet 1 C. A. PRATT MINING MACHINE Sept. 24, 1935.

Original Filed June 15, 1932 2 Sheets-Sheet 2 Patented Sept. 24, 1935 PATNT OFFIQE 7 MINING MACHINE Charles A. Pratt, Chicago, Ill., assignor to Goodman Manufacturing Company, Chicago, 111., a

corporation of Illinois Application June 15, 1932, Serial No. 617,273 Renewed April 6, 1934 20 Claims.

This invention relates to improvements in mining machines, and more particularly to improvements in a mining machine of the class adapted to be detachably mounted on a truck for transportatio-n .and slide on its bottom on the mine bottom during the cutting operation and has, as one of its principal objects, to provide a new and improved mining machine of the class described particularly adapted for operation in thin seams of coal and arranged with a view towards utmost simplicity, compactness, accessibility, and ease and efficiency in operation, together with a new and improved truck drive whereby the truck may be readily driven from the mining machine motor when the mining machine is mounted thereon.

Other objects of my invention will appear from time to time as this specification proceeds.

My invention may be more clearly understood with reference to the accompanying drawings wherein:

Figure l is a top plan View of the device embodying my invention mounted on a self-propelled truck with parts broken away and in section to more clearly show the details thereof;

Figure 2 is .an enlarged side elevation of the device shown in Figure l with parts brokenaway and in section to more clearly show the details thereof;

Figure 3 is a sectional view taken through the frictionally controlled gear reduction device; and

Figure 4 is a sectional view taken .along line 44 of Figure 1.

Like numerals refer to like parts throughout the several figures.

Referring now in particular to the drawings, the embodiment of my invention illustrated includes a main frame EB, which forms a support for the cutting and feeding mechanism, and a motor 2 l detachably secured to the rearward end of said main frame and adapted to rest directly on the mine bottom and substantially determining the height of the machine. The motor H has a vertically disposed armature shaft l2 for driving the feeding and cutting mechanism. A projecting cutter bar I4 is supported by and extends forwardly of the main frame It, and has a cutter chain i5 guided for movement thereabout in a usual manner. A feed drum [6 is supported on the advance side of the main frame It adjacent the forward end thereof for rotation about an axis disposed transversely thereof and has a flexible feeding member i'l adapted to be wound thereon for moving the mining machine about the mine and feeding it into and along the coal face.

- the armature shaft l2.

usual manner.

The mining machine is adapted to be detachably mounted on .a self-propelled truck [9 for movement about the mine on the mine .tracks from working place to working place in a usual manner. The truck i9 is of the usual drop front 5 type and is supported on track wheels 20 and axles 2!. A simplified and novel means is provided for driving the truck Hi from the mining machine motor I i in a manner which will hereinafter be more fully. explained.

As has before been mentioned, the motor I l is of the vertical type and is adapted to rest directly on the mine bottom and comprises a split motor casing 22 including a forward half 23 adapted to be detachably connectible to the rearward end 15 of the main frame H] by means of suitable nuts and bolts in a usual manner, and a rearward half 24 adapted to be detachably connectible to said forward half to facilitate ready removal of the armature and armature shaft I2 in a manner 20 which has been fully disclosed in an application Serial Number 595,054, filed by me on February 25, 1932.

Referring now in particular to the drive for the feed operating and cutter chain driving mechanism, and several of the novel features of my invention, an armature pinion 25 is provided on The armature pinion 25 meshes with and drives an idler gear 25 journaled on its hub in a suitable bearing support 21 secured to the upper portion of the main frame it in a usual manner, and extending rearwardly of said main frame over the motor casing 22. The idler gear 26 meshes with and drives a spur gear 29 journal-ed on its hub in the bearing support 2! in a suitable manner and keyed on the upper end of a vertical shaft 36.

A cutter chain drive sprocket 3| is journaled on its hub in a suitable bearing support secured to the main frame Ill and is freely mounted on the vertical shaft 33 adjacent the lower end thereof. The cutter chain sprocket 3| meshes with and is adapted to drive the cutter chain [5, and is selectively connectible with the vertical shaft 30 so it may be driven therefrom at 45 will by means of a suitable jaw clutch 32 in a The jaw clutch 32 is of a usual construction well known to those familiar with the art so will not herein be described in detail, and is operated by a clutch fork 33 secured to a rock shaft 34 disposed forwardly of the vertical shaft 30 and extending transversely of the main frame it. The rock shaft 34 is in turn operated by a suitable system of cranks and levers from the retreating side of the machine rearwardly of the main frame ID in a manner which will not herein be described in detail since it is no portion of my present invention.

Referring now in particular to the feed mechanism, the feed drum I6 is freely mounted on a suitable stud shaft 35 extending outwardly from the main frame Ill and has an internal gear 35 keyed to the inner periphery of a suitable flange extending inwardly from said drum. A pinion 3?, keyed on the outer end of a shaft 38, meshes with and drives the internal gear 36. A spur gear 39 is keyed on the opposite end of the shaft 33 and is driven from a spur pinion 48 keyed on the end of a transversely extending shaft 43. The transversely extending shaft 43 is adapted to be driven by a suitable frictionally controlled gear reduction mechanism, which may be of any type but which is herein preferably shown as being a gear reduction mechanism of the eccentric type generally indicated by reference character 44.

The gear reduction mechanism 44 includes a casing 45 journaled on its hub at one side thereof on a suitable sleeve 46 having its opposite side enclosed by an end member 41 journaled on a suitable clutch sleeve 48. The sleeve 46 is freely mounted on the transversely extending shaft 43 and has a spur gear 49 keyed thereto adjacent the outer side of the casing 45. The spur gear 49 is driven from a spur pinion 50 keyed on a transversely extending shaft 5! disposed forwardly of the transversely extending shaft 43. The transversely extending shaft 5| in turn is driven from the vertical shaft 38 by means of a bevel gear 53 keyed thereto, which bevel gear meshes with and drives a bevel gear 54 keyed on the inner end of the transversely extending shaft 5|.

The friotionally controlled eccentric gear reduction mechanism 44 is of a well known type, so will only herein be described insofar as is necessary to make my invention clearly understandable, and includes an eccentric 55 formed integral with an end of the sleeve 45 extending within the casing 45. A suitable ball bearing 5'! is mounted on the eccentric 55 and a spur gear 58 is mounted thereon. The spur gear 58 in turn meshes with and drives an internal gear 59 cut integral with a cage 60 and journaled within the casing 45 for free rotation with respect thereto. A plurality of lugs 6! are formed integral with the spur gear 58 and have suitable blocks 62 pivotally mounted thereon. The blocks 62 are in turn slidable in suitable guides in a usual manner so when the casing 45 is held from rotation by means of a suitable friction band 63,

which engages the outer periphery thereof in a usual manner, rotation of the eccentric 55 will move the spur gear 58 in a non-rotational closed orbital path which in turn will move the internal gear 59 a distance equal to the width of the number of teeth in the spur gear 58 which engage corresponding teeth in said internal gear in a usual manner well known to those skilled in the art. The speed of rotation of the internal gear 59 is reduced by lessening the pressure of the friction band 63 on the casing 45. Likewise, the casing 45 may slip within the friction band 63 upon overload of the internal gear 59 to prevent damage of the feed operating parts driven thereby in an obvious manner which will hereinafter be more fully described.

The friction band 63 is engaged with or disengaged from the casing 45 to vary the pressure thereon and speed of the feed drum is by means of a suitable system of levers in a usual manner,

not herein shown or described in detail since it is no portion of my present invention.

Suitable clutch means are provided for connecting the transversely extending shaft 43 with either the sleeve 45 or internal gear 59 so said shaft may be driven at a high speed or a slower frictionally controlled speed through the gear reduction mechanism 44, which means herein includes the clutch sleeve 48 which is feathered on the transversely extending shaft 43. The clutch sleeve 43 extends within the casing 45 and has suitable clutch jaws 54 formed integral therewith. The clutch jaws 64 are engageable with clutch jaws 65 formed integral with the cage 60 supporting the internal gear 59, or clutch jaws 65 formed integral with the sleeve 45. Thus when the clutch jaws 54 are engaged with the clutch jaws 55, the transversely extending shaft 43 and feed drum it? may be driven from the internal gear 59 at a slow frictionally controlled variable speed, and when said clutch jaws are engaged with the clutch jaws 56, the transversely extending shaft 43 and feed drum I6 may be driven from the sleeve 45 at a higher speed. The clutch sleeve 48 is shifted along the transversely extending shaft 43 by means of a suitable system of cranks and levers in a usual manner controlled from the retreating side of the machine, which will not herein be described in detail.

It may now be seen that a compact arrangement of gearing has been provided for driving the cutter chain and feed operating mechanism from the motor H, which gearing is so arranged as to permit the construction of a mining machine of minimum vertical dimensions and that the driving parts therefor are so arranged as to provide a maximum amount of space for the discharge of the cuttings from the retreating side of the main frame IQ. As herein shown, the means provided for discharging the cuttings to the retreating side of the main frame I3 comprise a forward wall 69 of the main frame H! so shaped as to conform substantially to the path traversed by the cutter chain [5 to permit said forward wall to cooperate with said cutter chain and enable said cutter chain to discharge the cuttings to the retreating side of the machine. With such an arrangement, a bottomless cuttings passageway is provided so the machine leaves the cuttings not discharged by the cutter chain behind as it travels along the coal face. Furthermore, the feed drum l5 and the reduction gearing for driving said feed drum from the motor 3! is so arranged that said reduction gearing is located above the cuttings passageway but beneath the uppermost extremities of the motor I! to provide ample space for the discharge of the cuttings from the machine frame and eliminate clogging of said cuttings in the cuttings passageway.

The flexible feeding member l! may be trained forwardly of the feed drum l6 around a suitable guide sheave 70 at the forward advance side of the machine to a mine jack or any other suitable holding means along the face of the coal for feeding the machine along the coal face, or said flexible feeding member may be trained rearwardly from said feed drum around suitable guide sheaves on the side of the machine, around a guide sheave H on the rearward advance side of the machine, and around a guide sheave l2 adjacent the central portion of the machine to a suitable connection on the truck 9 for drawing the mining machine upon said truck in a usual manner. The flexible feeding member I! may its normal direction of travel.

Suitable means are provided for controlling and retarding the rearward end of the machine as it is being fed along the coal face by the feed drum l 5, which means is herein preferably shown as being a frictionally controlled retarding drum' E4. The retarding drum I4 is freely mounted on a suitable stud "l extending rearwardly from the rearward end of the rearward half 26 of the motor casing22. Rotation of the retarding drum M is controlled by means of a suitable brake band it engageable with a suitable brake flange extending inwardly from said drum and operated by suitable lever means in a usual manner (not shown).

Referring now in particular to the means for.

driving the mining machine truck l9 from the motor II when said mining machine is mounted thereon, and several other of the novel features of my invention, a spur gear H is adapted to mesh with and be driven bythe armature pinion 25. The spur gear H is mounted in a suitable support member 18, in a usual manner, for rotation about a vertical axis. The support member 18 is U shaped and extends over a portion of the top and bottom surfaces of the spur gear 1? and is in turn pivotally mounted on a stud 19 extending upwardly from the rearward half 24 of the motor casing 22 and disposed eccentrically of the center of rotation of said spur gear. An arm 80 is integral with and extends from the support member l8 in a direction opposite its point of pivotal connection to'the motor casing 22. The arm 88 is adapted to move the support member 18 about its axis of pivotal connection to the motor casing 22 and is provided with a suitable aperture therein which is adapted to receive a locking pin 8!. The locking pin 8| is adapted to register for engagement with suitable apertures provided in the top surface of the motor casing 22 for locking the spur gear 11 in mesh with the armature pinion 25, or for looking said spur gear in a disengaged position from said armature pinion.

When the spur gear T! is meshed with the armature pinion 25 and the mining machine is pulled onto the truck I!) until its rearward end abuts suitable stops 9i, 9! on the mining machine truck, the spur gear I! meshes with and drives a spur gear 82 keyed on the upper end of a vertical shaft 83 journaled in a suitable housing and bearing bracket 84 for the truck driving mechanism secured to the rearward portion of the frame for the truck 19 in a usual manner.

A worm 85 is cut integral with the vertical shaft 83 and meshes with and drives a worm gear 86 keyed on a'transversely extending shaft 8'! journaled in the housing and bearing bracket 8d. The transversely extending shaft 87 extends outwardly beyond the boundaries of the truck l9 and has a sprocket 88 secured thereto, which sprocket has connection with the rearward truck axle 2| and wheels 20 by means of a suitable chain and sprocket drive indicated by reference character 89 in a usual manner. The forward and rearward truck axles 2| and truck wheels 20 are in turn connected together by a suitable chain and'sprocket drive indicated by reference character 90.

It may thus be seen that when the mining machine has been pulled onto the truck i9 by means of the flexible feeding member I! and is 5 positioned thereon so its rearward end abuts the stops 9|, 9|, said truck may be driven from the motor for driving the mining machine operating parts by means of the spur gear Ti meshing with and driven by the armature pinion 25 and the 10 spur gear 82 supported on the truck and driven from the spur gear 11 and a suitable drive connection driven from the spur gear 82. Thus a means has been provided for driving the truck from the mining machine motor so arranged 15 as to aiford an efficient and compact detachable drive of a simplified construction.

Although I have herein shown and described one embodiment of my invention, it will be understood that the construction and arrangement of the various parts may be altered without departing from the spirit and scope thereof. Furthermore, I .do not wish tobe construed as limiting myself to the specific form illustrated, excepting as it may be specifically limited in the appended claims.

I claim as my invention:

1. In a mining machine, a main frame adapted to rest upon and slide over the mine bottom, a

motor disposed rearwardly of said frame and including a vertically disposed armature shaft, a pinion on said shaft, cutting mechanism driven by said pinion and carried by said frame in advance of said motor and. including a forwardly projecting chain carrying cutter bar, feeding mechanism carried by said frame forwardly of said motor and including a feed operating member adapted to cooperate directly with a flexible feeding member and truck driving mechanism driven by said motor including a truck driving element carried by said motor for selective engagement with said pinion and disposed for rotation about a vertical axis.

2. In a mining machine, a main frame adapted to rest upon and slide over the mine bottom, a motor disposed rearwardly of said frame, said motor being detachably connectible with said frame and slidable directly on the mine bottom and having an armature shaft rotatable about a vertical axis, a pinion on the upper end of said armature shaft, cutting mechanism driven by said pinion and carried by said frame in advance of said motor including a forwardly projecting chain carrying cutter bar, feeding mechanism driven by said motor and carried by said frame forwardly of said motor and including a feed operating member adapted to cooperate directly with a flexible feeding member, and truck driving mechanism driven by said motor including. a truck driving element selectively engageable with said pinion and carried by said motor for rotation about a vertical axis.

3. In a mining machine, a main frame adapted to rest upon and slide over the mine bottom, a motor disposed rearwardly of said frame, said 5 motor being detachably connectible with said frame and slidable directly on the mine bottom and having an armature shaft rotatable about a vertical axis, cutting mechanism driven by said motor and carried by said frame in advance of said motor including a forwardly projecting chain carrying cutter bar, feeding mechanism driven by said motor and carried by said frame forwardly of said motor and including a feed operating member adapted to cooperate directly with a flexible feeding member, and truck driving mechanism driven by said motor including. a truck driving element carried by said motor on the upper side thereof rearwardly of said armature shaft and rotatable about a vertical axis.

4. In a mining machine, a main frame adapted to rest upon and slide over the mine bottom, a motor disposed rearwardly of said frame, said motor being detachably connectible with said frame and slidable directly on the mine bottom and having an armature shaft rotatable about a vertical axis, cutting mechanism driven by said motor and carried by said frame in advance of said motor including a forwardly projecting chain carrying cutter bar, feeding mechanism driven by said motor and carried by said frame forwardly of said motor and including a feed operating member adapted to cooperate directly with a flexible feeding member, and truck driving mechanism driven by said motor including a truck driving element selectively connectible with said motor and carried thereby rearwardly of said armature shaft.

5. In a room and pillar mining machine, a motor adapted to rest on and slide along the mine bottom, said motor substantially determining the height of the machine and having a vertical armature shaft, a main frame disposed forwardly of said motor and detachably connectible thereto, feeding mechanism supported on said main frame adjacent the forward advance side thereof comprising a feed drum rotatable about an axis extending transversely of said main frame, cutting mechanism supported on said main frame including a projecting chain carrying cutter bar, means for driving said feeding and cutting mechanism from said motor including a pinion on the upper end of said armature shaft, and truck driving mechanism driven by said motor including a truck driving. element carried by said motor and disposed for rotation about a vertical axis.

6. In a room and pillar mining machine, a motor having a vertical armature shaft, said motor being adapted to rest on and slide along the mine bottom and substantially determining the height of the machine, a main frame disposed forwardly of said motor and detachably connectible thereto, feeding mechanism supported on said main frame adjacent the forward advance side thereof comprising a feed drum rotatable about an axis extending transversely of said main frame, cutting mechanism supported on said main frame including a projecting chain carrying cutter bar, means for driving said feeding and cutting. mechanism from said motor including a pinion on the upper end of said armature shaft, and truck driving mecha nism driven by said motor including a truck driving element carried by said motor on the upper side thereof and driven from said armature pinion.

'7. In a room and pillar mining machine, a motor having a vertical armature shaft, said motor being adapted to rest on and slide along the mine bottom and substantially determining the height of the machine, a main frame disposed forwardly of said motor and detachably connectible thereto, feeding mechanism supported on said main frame adjacent the forward advance side thereof comprising a feed drum rotatable about an axis extending transversely of said main frame, cutting mechanism supported on said main frame including a projecting chain carrying cutter bar, means for driving said feeding and cutting mechanism from said motor including a pinion on the upper end of said armature shaft, and truck driving mechanism driven by said motor including a spur gear carried by said motor and means for selectively engaging said spur gear with said armature pinion.

8. In a room and pillar mining machine, a motor having a vertical armature shaft, said motor being adapted to rest on and slide along the mine bottom and substantially determining the height of the machine, a main frame disposed forwardly of said motor and detachably connectible thereto, feeding mechanism supported on said main frame adjacent the forward advance side thereof comprising a feed drum rotatable about an axis extending transversely of said main frame, cutting mechanism supported on said main frame including a projecting chain carrying cutter bar, means for driving said feeding and cutting mechanism from said motor including a pinion on the upper end of said armature shaft, and truck driving mechanism driven by said motor including a spur gear carried by said motor and means for selectively engaging said spur gear with said armature pinion comprising a support for said spur gear mounted on said motor for movement about an axis eccentric of the axis of rotation of said spur gear.

9. In a room and pillar mining machine, a motor having a vertical armature shaft, said motor being adapted to rest on and slide along the mine bottom and substantially determining the height of the machine, a main frame disposed forwardly of said motor and detachably connectible thereto, feeding mechanism supported on said main frame adjacent the forward advance side thereof com prising a feed drum rotatable about an axis extending transversely of said main frame, cutting mechanism supported on said main frame including a projecting chain carrying cutter bar, means for driving said feeding and cutting mechanism from said motor including a pinion on the upper end of said armature shaft, and truck driving mechanism driven by said motor including a spur gear carried by said motor, means for selectively engaging said spur gear with said armature pinion comprising a support for said spur gear mounted on said motor for movement about an axis eccentric of the axis of rotation of said spur gear, and locking means therefor for locking said spur gear in a meshed or disengaged position with said armature pinion.

10. In a mining apparatus, a wheeled truck, a mining machine slidable longitudinally of said wheeled truck, said mining machine including a motor having a vertical armature shaft and having a main frame extending forwardly therefrom carrying feed operating and cutter chain driving mechanism, and a drive connection from said mining machine motor to said truck comprising a pinion on said armature shaft and a truck driving element driven by said armature shaft and including a spur gear selectively engageable with said pinion mounted on the upper side of said motor for rotation about a vertical axis.

11. In a mining apparatus, a wheeled truck, a

from said motor including a spur gear mounted on said motor on the upper side thereof adapted to selectively mesh with said armature pinionand a gear on said truck adapted to be meshed with said spur gear.

12. In a mining apparatus, a wheeled truck, a mining machine slidable longitudinally of said wheeled truck, said mining machine including a motor having a vertical armature shaft and havring a main frame extending forwardly therefrom carrying feed operating and cutter chain driving mechanism, means for driving said feed operating and cutter chain driving mechanism from said motor including a pinion on the upper end --of said armature shaft and selective drive connections therefrom, and means for driving said truck from said motor including a spur gear carried by said motor on the upper side thereof and means for selectively engaging said spur gear with zo said armature pinion.

13. In a mining apparatus, a wheeled truck, a mining machine slidable longitudinally. of said wheeled truck, said mining machine including a motor having a vertical armature shaft and having a main frame extending forwardly therefrom carrying feed operating and cutter chain driving mechanism, means for driving said feed operating and cutter chain driving mechanism from said motor including a pinion on the upper end of said armature shaft and selective drive connections therefrom, and means for driving said truck from said motor including a spur gear carried by said motor on the upper side thereof and means for selectively engaging said spur gear with said sa -armature pinion comprising a support for said spur gear mounted on the upper surface of said motor for movement about an axis eccentric of the axis of rotation of said spur gear.

14. In a mining apparatus, a wheeled truck, a

40 mining machine slidable longitudinally of said Wheeled truck, said mining machine including a motor having a vertical armature shaft and having a main frame extending forwardly therefrom carrying feed operating and cutter chain driv- 5 ing mechanism, means for driving said feed operating and cutter chain driving mechanism from said motor including a pinion on the upper end of said armature shaft and selective drive connections therefrom, and means for driving said 5 truck from said motor including a spur gear carried by said motor on the upper side thereof, means for selectively engaging said spur gear with said armature pinion comprising a support for said spur gear mounted on theupper surface 55 of said motor for movement about an axis eccentric of the axis of rotation of said spur gear, and locking means therefor for locking said spur gear in a meshed or disengaged position with said armature pinion.

60 15. v In a mining machine, a main frame adapted to rest upon and slide over the mine bottom, a motor disposed rearwardly of said frame, said motor being detachably connectible with said frame and slidable directly on the mine bottom 5 and having an armature shaft rotatable about a vertical axis, cutting mechanism driven by said motor and carried by said frame in advance of said motor including a forwardly projecting chain carrying cutter bar, feeding mechanism driven 70 by said motor and carried by said frame forwardly of said motor and including a feed operating member adapted to cooperate directly with a flexible feeding member, means for selectively driving said cutting mechanism from said motor 75 including a drive shaft driven from said armature pinion and rotatable about a vertical axis and'means for selectively driving said feed operating member from said drive shaft comprising a bevel gear thereon, another bevel gear driven thereby; a frictionally controlled gear reduction 5 ,ed to rest .upon and slide over the mine bottom, a

motor disposed rearwardly of said frame, said 15 motor being detachably connectible with said frame and slidable directly on the mine bottom and having an armature shaft rotatable about a vertical axis, cutting mechanism driven by said motor and carried by saidframe in advance of 20.

said motor including a forwardly projecting chain carrying cutter bar, feeding mechanism driven by said motor and carried by said frame forwardly of said motor and including a feed operating member adapted to cooperate directly with a 25- flexible feeding member, means for selectively driving said cutting mechanism from said motor including'a drive shaft driven from said armature pinion and rotatable about a vertical axis, means for selectively driving said feed operating 30 member from said drive shaft comprising a bevel gear thereon, another bevel gear driven thereby, a frictionally controlled gear reduction device driven by said bevel gear and disposed on a side of said main frame opposite from said feed operating member and a geared connection from said frictionally controlled gear reduction device to said feed operating member, and truck driving mechanism driven by said motor including a truck driving element driven from said armature I pinion and carried by said motor for rotation about a vertical axis.

1'7. In a mining machine, a main frame adapted to rest upon and slide over the mine bottom, a motor disposed rearwardly of said frame, said motor being detachably connectible with said frame and slidable directly on the mine bottom and having an armature shaft rotatable about a vertical axis, cutting mechanism driven by said motor and carried by said frame in advance of said motor including a forwardly projecting chain carrying cutter bar, feeding mechanism driven by said motor and carried by said frame forwardly of said motor and including a feed operating member adapted to cooperate directly with a flexible feeding member, means for selectively driving said cutting mechanism from said motor including a drive shaft driven from said armature pinion and rotatable about a vertical axis, means for selectively driving said feed operating 0 member from said drive shaft comprising a bevel gear thereon, another bevel gear driven thereby, a frictionally controlled gear reduction device driven by said bevel gear and disposed on a side of said main frame opposite from said feed operat- 5 ing member and a geared connection from said frictionally controlled gear reduction device to said feed operating member, and truck driving mechanism driven by said motor including a truck driving element selectively connectible with said 7 armature pinion and carried by said motor on the upper side thereof rearwardly of said armature shaft for rotation about a vertical axis.

18. In a mining machine, a main frame adapted to rest upon the slide over the mine bottom, a 7

, ing said cutting mechanism from said motor including a drive shaft driven from said armature pinion and rotatable about a vertical axis, means for selectively driving said feed operating member from said drive shaft comprising a bevel gear thereon, another bevel gear driven thereby, a frictionally controlled gear reduction device driven by said bevel gear and disposed on a side of said main frame opposite from said feed operating member and a geared connection from said frictionally controlled gear reduction device to said feed operating member, and truck driving mech- Janism driven by said motor including a truck driving element selectively connectible with said armature pinion and carried by said motor on the upper side thereof rearwardly of said armature shaft for rotation about a vertical axis and means for selectively engaging said truck driving element with said armature pinion.

19. In a mining machine, a main frame adapted to rest upon and slide over the mine bottom, a motor disposed rearwardly of said frame, said 'tmotor being detachably connectible with said frame and slidable directly on the mine bottom and having an armature shaft rotatable about a vertical axis, cutting mechanism driven by said motor and carried by said frame in advance of said motor including a forwardly projecting chain carrying cutter bar, feeding mechanism driven by frictionally controlled gear reduction device driven by said bevel gear and disposed on a side of said main frame opposite from said feed operating member and a geared connection from said frictionally controlled gear reduction device to said feed operating member, and truck driving mechanism driven by said motor including a truck driving element selectively connectible with said armature pinion andcarried by said motor on the upper side thereof rearwardly of said armature shaft for rotation about a vertical axis and means for selectively engaging said truck driving element with said armature pinion comprising a support for said spur gear mounted on said motor for movement about an axis eccentric of the axis of rotation of said truck driving element.

20. In a mining machine, a main frame adapted to rest upon and slide along the ground, a motor including an armature shaft, a pinion on said armature shaft, cutting mechanism driven by said motor including a forwardly projecting cutter bar, feeding mechanism therefor including a winding drum having a flexible feeding member thereon disposed to one side of said main frame, and truck driving mechanism including a truck driving element selectively engageable with said pinion mounted on said motor and disposed for rotation about an axis parallel to the axis of rotation of said armature shaft.

CHARLES A. PRA'I'I. 

